Technology is evolving at an amazing pace. More and more information can be communicated over an RF medium to an individual. It is becoming commonplace for individuals to carry with them, or be within easy access, of a variety of wireless communication devices. One such communication device, for example, is a PCS (personal communication services) phone. The types of services provided thereby may include telephone interconnect calling, reception of data transmissions and/or certain voice transmissions, private calling, group calling, etc. Generally, such devices are part of a large radio communication system consisting of a communication resource controller and one or more communication resources where the communication resources may be an RF channel, a pair of RF channels, a TDM slot, or any medium for carrying RF signals.
Pagers, including alphanumeric display pagers and pagers with voice mail capability for storing voice messages, are another type of communication device. Paging systems are well known and like conventional wireless telephony systems also typically comprise a resource controller communicating over selected coverage areas using predefined communication resources. More modern technologies, such as PCS phones, provide a broad scope of wireless communication devices by integrating voice, data and paging, by way of example, into a unitary, integrated communication system. A PCS user can have access to a variety of services of incompatible format all from a single portable unit. Other types of fast emerging communication devices are portable (hand-held) graphics terminals, such as Motorola's Personal Digital Assistant (PDA). Portable graphics terminals display data, transmitted over a wireless RF medium from a central controller in a PDA system, in graphical form.
In situations where different services are not integrated into one communication system, each device associated with a particular system is typically assigned a unique user id. That id is typically unique to the device, and an individual has a different id for each device (phone, pager, PDA, etc.) which he may carry with him. When a communication message is desired to be sent to a specified user id, to initiate the communication--for example in a trunked radio system--a calling unit or device places a request to its associated resource controller via a communication resource dedicated for control information (control channel). The communication request can include a request for a particular service, such as allocation of a communication resource and includes the identity of a target (receiving) communication device (or devices if group call).
Upon receiving a request to transmit a call (message) in a format specific to the system in which the call (message) was initiated, the communication resource controller of that system in which the call (message) was initiated determines whether the target unit is registered, or otherwise in a state ready to receive the call (message).
If ready, then the resource controller grants the request. If not ready, such as when a target device is temporarily in a power-down mode, or currently involved in another call, out-of-range, out-of-service, etc., then the call (message) transmission to the target might be aborted. To illustrate, assuming a voice message is attempted to a portable radio carried by a businessman on travel, but whose phone may be out-of-range, left home, etc., that individual would not be able to receive, or even be aware, of any incoming calls. Although this same individual may have with him another device(s) such as for example a pager, a laptop, a PDA, etc., currently there is no way to be able to direct the voice message to another device. One obvious reason for this difficulty is that the respective network systems servicing the various user devices available to the individual are typically stand-alone, non-integrated, non-communicating systems. Another reason is that these systems lack the functionality to convert incoming messages in one format (e.g., text) to another format (e.g., voice). This is crucial because an alphanumeric display pager cannot process voice messages, and a portable phone cannot voice a text message.
U.S. Pat. Nos. 5,555,376 and 5,493,692 to Theimer et al. generally teach methods to deliver messages to mobile users, e.g., within an office building, on devices, e.g., computer terminals or printers, that the users are in proximity to. To determine where people are in relation to plural communication devices disposed throughout a given geographic location, the use of a separate location facility such as an RF tag badge network (or even GPS receivers) is proposed. When the target device is a display device, the communication system includes functionality, by way of a central agent, which determines which proximal display device provides sufficient privacy for a given transmission. The system determines the communication path from the agent to the user. The disclosed methods are merely an extended form of message call-forwarding to a target device capable of receiving the message in its original transmission. The Theimer patents make possible tracking, for example, an individual's location and forwarding a phone (voice) call message to a phone or mobile unit closest in proximity. The forwarding decision does not involve forwarding a message in one type format (e.g., a voice transmission directed to a currently non-registered specified unit of an identifiable user) to another communication device which is currently active but which is not designed to recognize voice transmissions received in the format of the original target unit.
The conversion of information in one file format to another file format prior to transmission is well known and forms no part of the present invention. While message format transformation is well known for various applications, such as for example converting an email message to voice for retrieval of same over a telephony system, it is not known to provide a means which automatically performs data transformation on the content of a call or message when the original target device is unavailable.
Commonly assigned U.S. Pat. No. 5,594,947 to Grube et al. discloses a method for providing alternate communication services to a target unit. A decision is made by the central controller in a radio communication system as to whether certain types of RF transmissions, from a source unit, are to be prohibited as a function of a target unit's present geographic location. If so, the request for communication with the target is denied and an alternative service request to the same unit, may be automatically processed by the central controller instead. Here again, there is no transformation of data from one file format, corresponding to that of an original target unit associated with a given communication network, to that of a second file format, corresponding to that of an automatically selected alternative target unit associated with a different communication network.